Integrated circuits with integrated oscillator circuitry that do not require an external component are difficult to design with high precision. For example, some circuits with internal oscillators can achieve a precision of ±1% over temperature after calibration. However, when a higher precision is required, an external crystal or clock recovery is required to achieve the respective precision.
For example, the Controller Area Network bus is a bus standard originally designed for vehicles that allows devices to communicate without a host computer. An enhancement of the standard is known as CAN with Flexible Data Rate (CANFD). The CANFD standard, however, requires advanced precision. In particular, the required precision may be on the order of 0.4%. Integrated devices implementing this or other standards/applications with such high precision may require external components or require advanced circuitry to achieve the required precision. Hence, there exists a need for an improved clock oscillator for digital systems.